Pregnancy-associated gynecological cancer in New South Wales, Australia 1994-2013: A population-based historical cohort study.

INTRODUCTION: Pregnancy-associated gynecological cancer (PAGC) refers to cancers of the ovary, uterus, fallopian tube, cervix, vagina, and vulva diagnosed during pregnancy or within 12 months postpartum. We aimed to describe the incidence of, and perinatal outcomes associated with, invasive pregnancy-associated gynecological cancer. MATERIAL AND METHODS: We conducted a population-based historical cohort study using linked data from New South Wales, Australia. We included all women who gave birth between 1994 and 2013, with a follow-up period extending to September 30, 2018. Three groups were analyzed: a gestational PAGC group (women diagnosed during pregnancy), a postpartum PAGC group (women diagnosed within 1 year of giving birth), and a control group (women with control diagnosis during pregnancy or within 1 year of giving birth). We used generalized estimation equations to compare perinatal outcomes between study groups. RESULTS: There were 1 786 137 deliveries during the study period; 70 women were diagnosed with gestational PAGC and 191 with postpartum PAGC. The incidence of PAGC was 14.6/100 000 deliveries and did not change during the study period. Women with gestational PAGC (adjusted odds ratio [aAOR] 6.81, 95% confidence interval [CI] 2.97-15.62) and with postpartum PAGC (aOR 2.65, 95% CI 1.25-5.61) had significantly increased odds of a severe maternal morbidity outcome compared with the control group. Babies born to women with gestational PAGC were more likely to be born preterm (aOR 3.11, 95% CI 1.47-6.59) and were at increased odds of severe neonatal complications (aOR 3.47, 95% CI 1.45-8.31) compared with babies born to women without PAC. CONCLUSIONS: The incidence of PAGC has not increased over time perhaps reflecting, in part, the effectiveness of cervical screening and early impacts of human papillomavirus vaccination programs in Australia. The higher rate of preterm birth among the gestational PAGC group is associated with adverse outcomes in babies born to these women.

Evaluating the reach and impact of Still Six Lives: A national stillbirth public awareness campaign in Australia.

BACKGROUND: The Still Six Lives campaign aimed to increase awareness of stillbirth among Australian women and educate people about three modifiable behaviours that pregnant women could take to reduce the risk of stillbirth. The campaign used earned media, digital advertising and social media. AIM: The aim of this study is to evaluate the impact of the campaign on Australian women's awareness of stillbirth, and knowledge of the three modifiable behaviours. METHODS: The study collected process evaluation data about campaign implementation from digital platforms. The impact evaluation comprised of two components: a three-wave community survey of Australian women aged 18-50 years old, and a pre-post cross-sectional maternity service survey of pregnant women. RESULTS: The campaign gained significant reach, including 2,974,375 completed video views and 910,000 impressions via social media influencers. The community surveys had 1502 participants at baseline, 1517 mid-campaign and 1598 post-campaign. Participants were slightly more likely to have encountered messages about stillbirth after the campaign (aOR 1.30, 95% CI 1.09-1.55). There were increases in awareness of each behaviour after the campaign: be aware of baby's movements (aOR 1.26, 95% CI 1.08-1.47), quit smoking (aOR 1.27, 95% CI 1.10-1.47) and going-to-sleep on side (aOR 1.55, 95% CI 1.32-1.82). The antenatal clinic survey had 296 participants at baseline and 178 post-campaign. Post-campaign, there was an increased likelihood that women were aware of side-sleeping (aOR 3.11, 95% CI 1.74-5.56). CONCLUSIONS: The national campaign demonstrated some evidence of change in awareness of three modifiable behaviours that can reduce the risk of stillbirth.

Pregnancy associated cancer, timing of birth and clinical decision making-a NSW data linkage study.

BACKGROUND: The incidence of pregnancy-associated cancer (PAC), comprising cancer diagnosed during pregnancy or within one year postpartum, is increasing. We investigated the obstetric management and outcomes of women with PAC and their babies. METHODS: A population-based observational study of all women who gave birth between 1994 and 2013 in New South Wales, Australia. Women were stratified into three groups: those diagnosed during pregnancy (gestational cancer group), those diagnosed within one year of giving birth (postpartum cancer group), and a no-PAC group. Generalized estimating equations were used to examine the association between PAC and adverse maternal and neonatal outcomes. RESULTS: One million seven hundred eighty-eight thousand four hundred fifty-onepregnancies were included-601 women (614 babies) were in the gestational cancer group, 1772 women (1816 babies) in the postpartum cancer group, and 1,786,078 women (1,813,292 babies) in the no-PAC group. The overall crude incidence of PAC was 132.7/100,000 women giving birth. The incidence of PAC increased significantly over the twenty-year study period from 93.5/100,000 in 1994 to 162.5/100,000 in 2013 (2.7% increase per year, 95% CI 1.9 - 3.4%, p-value < 0.001). This increase was independent of maternal age. The odds of serious maternal complications (such as acute abdomen, acute renal failure, and hysterectomy) were significantly higher in the gestational cancer group (adjusted odds ratio (AOR) 5.07, 95% CI 3.72 - 6.90) and the postpartum cancer group (AOR 1.55, 95% CI 1.16 - 2.09). There was no increased risk of perinatal mortality in babies born to women with PAC. However, babies of women with gestational cancer (AOR 8.96, 95% CI 6.96 - 11.53) or postpartum cancer (AOR 1.36, 95% CI 1.05 - 1.81) were more likely to be planned preterm birth. Furthermore, babies of women with gestational cancer had increased odds of a severe neonatal adverse outcome (AOR 3.13, 95% CI 2.52 - 4.35). CONCLUSION: Women with PAC are more likely to have serious maternal complications. While their babies are not at increased risk of perinatal mortality, they are more likely to experience poorer perinatal outcomes associated with preterm birth. The higher rate of birth intervention among women with gestational cancers reflects the complexity of clinical decision-making in this context.

Growth and risk of adverse neuro-developmental outcome in infants with congenital heart disease: A systematic review.

AIM: Congenital heart disease (CHD) is one of the most common birth defects affecting around 1:100 infants. In this systematic review, we aimed to determine impact of growth on neurodevelopmental outcomes of infants with CHD. METHODS: Studies that reported association of growth with developmental outcomes in infants with CHD who had surgery, were included. The search strategy was prospectively registered. Relevant studies were identified by electronic searches. The Cochrane Central Register of Controlled Trials, MEDLINE and EMBASE were searched from their earliest date to February 2022. RESULTS: Twenty studies met inclusion criteria. Choice of growth measures, developmental assessment tools and timing of assessment varied widely precluding conduct of a meta-analysis. Seventeen studies reported on infants who had cardio-pulmonary bypass. Birth weight was reported in thirteen studies and was associated with adverse outcome in nine. Head circumference at birth and later predicted developmental outcomes in five. Impaired postnatal growth was associated with adverse developmental outcome in seven studies. CONCLUSION: Growth in infants with congenital heart disease, specifically single ventricle physiology can predict adverse neurodevelopmental outcome. Included studies showed significant clinical heterogeneity. Uniformity should be agreed by various data registries with routine prospective collection of growth and developmental data.

Growth and risk of adverse neurodevelopmental outcome in infants with congenital surgical anomalies: a systematic review.

Survival of infants with congenital anomalies requiring surgical correction has increased dramatically, shifting the focus of clinical care and research toward optimising growth and neurodevelopment.To determine the impact of growth on neurodevelopmental outcomes of infants with congenital surgical anomalies. Studies that reported association of growth with developmental outcomes in infants with congenital anomalies who had surgery, were eligible for inclusion. The search strategy was prospectively drafted, and relevant studies were identified by electronic searches. The Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library 2022, issue 1), MEDLINE and EMBASE from their earliest date to February 2022 were searched. Seven studies met the inclusion criteria. Variability in selection of growth measures, developmental assessment tools and assessment endpoints for neurodevelopment, precluded a meta-analysis. Four studies reported the association between growth and neurodevelopmental outcomes in infants with gastroschisis with two noting adverse outcomes in infants who were small for gestational age. Birthweight, reported in four studies, was not associated with adverse developmental outcomes. Postnatal growth, reported in three studies, was associated with adverse outcome. The data linking growth restriction in infants with congenital surgical anomalies and neurodevelopmental outcome is limited. There is limited published research examining the longitudinal effects of intra- and extra-uterine growth parameters on neurodevelopmental outcomes.

Associations between symptoms of sleep-disordered breathing and maternal sleep patterns with late stillbirth: Findings from an individual participant data meta-analysis.

BACKGROUND AND OBJECTIVES: Sleep-disordered breathing (SDB) affects up to one third of women during late pregnancy and is associated with adverse pregnancy outcomes, including hypertension, diabetes, impaired fetal growth, and preterm birth. However, it is unclear if SDB is associated with late stillbirth (≥28 weeks' gestation). The aim of this study was to investigate the relationship between self-reported symptoms of SDB and late stillbirth. METHODS: Data were obtained from five case-control studies (cases 851, controls 2257) from New Zealand (2 studies), Australia, the United Kingdom, and an international study. This was a secondary analysis of an individual participant data meta-analysis that investigated maternal going-to-sleep position and late stillbirth, with a one-stage approach stratified by study and site. Inclusion criteria: singleton, non-anomalous pregnancy, ≥28 weeks' gestation. Sleep data ('any' snoring, habitual snoring ≥3 nights per week, the Berlin Questionnaire [BQ], sleep quality, sleep duration, restless sleep, daytime sleepiness, and daytime naps) were collected by self-report for the month before stillbirth. Multivariable analysis adjusted for known major risk factors for stillbirth, including maternal age, body mass index (BMI kg/m2), ethnicity, parity, education, marital status, pre-existing hypertension and diabetes, smoking, recreational drug use, baby birthweight centile, fetal movement, supine going-to-sleep position, getting up to use the toilet, measures of SDB and maternal sleep patterns significant in univariable analysis (habitual snoring, the BQ, sleep duration, restless sleep, and daytime naps). Registration number: PROSPERO, CRD42017047703. RESULTS: In the last month, a positive BQ (adjusted odds ratio [aOR] 1.44, 95% confidence interval [CI] 1.02-2.04), sleep duration >9 hours (aOR 1.82, 95% CI 1.14-2.90), daily daytime naps (aOR 1.52, 95% CI 1.02-2.28) and restless sleep greater than average (aOR 0.62, 95% CI 0.44-0.88) were independently related to the odds of late stillbirth. 'Any' snoring, habitual snoring, sleep quality, daytime sleepiness, and a positive BQ excluding the BMI criterion, were not associated. CONCLUSION: A positive BQ, long sleep duration >9 hours, and daily daytime naps last month were associated with increased odds of late stillbirth, while sleep that is more restless than average was associated with reduced odds. Pregnant women may be reassured that the commonly reported restless sleep of late pregnancy may be physiological and associated with a reduced risk of late stillbirth.

Epigenetic aging in newborns: role of maternal diet.

BACKGROUND: Epigenetic aging is associated with higher risk of cardiovascular disease, cancer, and all-cause mortality and may be a mechanistic link between early-life exposures, such as maternal dietary characteristics during pregnancy, and risk of adult disease. OBJECTIVES: We sought to determine the early-life risk factors for newborn epigenetic aging, specifically maternal dietary macronutrient intake, and whether epigenetic aging is associated with cardiovascular health markers in the newborn. METHODS: Epigenetic age acceleration of 169 newborns was measured from saliva using the Horvath age calculator. Maternal diet during pregnancy was assessed using food-frequency questionnaires. RESULTS: Newborns with positive age acceleration were more likely to be female and have greater body fatness. Maternal intakes of saturated fat [6.2 wk epigenetic age acceleration (95% CI: 1.0, 11.3) per 5% of energy; P = 0.02] and monounsaturated fat [12.4 wk (95% CI: 4.2, 20.5) per 5% of energy; P = 0.003] were associated with higher epigenetic age acceleration in the newborn. The strongest association of individual fatty acids were for palmitoleic acid (25.3 wk; 95% CI: 11.4, 39.2; P = 0.0004), oleic acid (2.2 wk; 95% CI: 0.8, 3.6; P = 0.002), and palmitic acid (2.9 wk; 95% CI: 1.0, 4.9; P = 0.004) per 1% of energy intake. Vitamin D supplementation was associated with lower epigenetic age acceleration (-8.1 wk; 95% CI: -14.5, -1.7; P = 0.01). Epigenetic age acceleration was associated with aortic intima-media thickness in preterm infants [1.0 µm (95% CI: 0.2, 1.8) per week of epigenetic age acceleration; P = 0.01], but not among those born at term (P = 0.78). Epigenetic age acceleration was not associated with heart rate variability in either preterm or term born infants (both P > 0.2). CONCLUSIONS: This study provides evidence of maternal dietary characteristics that are associated with epigenetic aging in the offspring. Prospective intervention studies are required to determine whether such associations are causal.

The relationship between maternal adiposity during pregnancy and fetal kidney development and kidney function in infants: the Gomeroi gaaynggal study.

Maternal obesity during pregnancy has a detrimental impact on offspring renal development and function. This is pertinent to Indigenous Australians as they are twice as likely as non-Indigenous Australians to develop chronic kidney disease (CKD). The aim of this study was to examine whether there was an association between maternal adiposity and fetal kidney growth in late gestation (>28 weeks) and kidney function in infants, <2.5 years of age, from the Gomeroi gaaynggal cohort. Pre-pregnancy body mass index (BMI) was recorded at the first prenatal visit and maternal adiposity indicators (percent body fat and visceral fat area) measured at >28 weeks gestation by bioelectrical impedance analysis. Fetal kidney structure was assessed by ultrasound. Renal function indicators (urinary albumin:creatinine and protein:creatinine) were measured in infants from a spot urine collection from nappies. Multiple linear regression and multi-level mixed effects linear regression models with clustering were used to account for repeated measures of urine. 147 mother-child pairs were examined. Estimated fetal weight (EFW), but not fetal kidney size, was positively associated with maternal adiposity and pre-pregnancy BMI. When adjusted for smoking, combined kidney volume relative to EFW was negatively associated with maternal percentage body fat. Infant kidney function was not influenced by maternal adiposity and pre-pregnancy BMI (n = 84 observations). Current findings show that Indigenous babies born to obese mothers have reduced kidney size relative to EFW. We suggest that these babies are experiencing a degree of glomerular hyperfiltration in utero, and therefore are at risk of developing CKD in later life, especially if their propensity for obesity is maintained. Although no impact on renal function was observed at <2.5 years of age, long-term follow-up of offspring is required to evaluate potential later life impacts.

An Individual Participant Data Meta-analysis of Maternal Going-to-Sleep Position, Interactions with Fetal Vulnerability, and the Risk of Late Stillbirth.

BACKGROUND: Maternal supine going-to-sleep position has been associated with increased risk of late stillbirth (≥ 28 weeks), but it is unknown if the risk differs between right and left side, and if some pregnancies are more vulnerable. METHODS: Systematic searches were undertaken for an individual-level participant data (IPD) meta-analysis of case-control studies, prospective cohort studies and randomised trials undertaken up until 26 Jan, 2018, that reported data on maternal going-to-sleep position and stillbirth. Participant inclusion criteria included gestation ≥ 28 weeks', non-anomalous, singleton pregnancies. The primary outcome was stillbirth. A one-stage approach stratified by study and site was used for the meta-analysis. The interaction between supine going-to-sleep position and fetal vulnerability was assessed by bi-variable regression. The multivariable model was adjusted for a priori confounders. Registration number: PROSPERO, CRD42017047703. FINDINGS: Six case-control studies were identified, with data obtained from five (cases, n = 851; controls, n = 2257). No data was provided by a sixth study (cases, n = 100; controls, n = 200). Supine going-to-sleep position was associated with increased odds of late stillbirth (adjusted odds ratio [aOR] 2.63, 95% CI 1.72-4.04, p < 0.0001) compared with left side. Right side had similar odds to left (aOR 1.04, 95% CI 0.83-1.31, p = 0.75). There were no significant interactions between supine going-to-sleep position and assessed indicators of fetal vulnerability, including small-for-gestational-age infants (p = 0.32), maternal obesity (p = 0.08), and smoking (p = 0.86). The population attributable risk for supine going-to-sleep position was 5.8% (3.2-9.2). INTERPRETATION: This IPD meta-analysis confirms that supine going-to-sleep position is independently associated with late stillbirth. Going-to-sleep on left or right side appears equally safe. No significant interactions with our assessed indicators of fetal vulnerability were identified, therefore, supine going-to-sleep position can be considered a contributing factor for late stillbirth in all pregnancies. This finding could reduce late stillbirth by 5.8% if every pregnant woman ≥ 28 weeks' gestation settled to sleep on her side.

Understanding and provision of preconception care by general practitioners.

BACKGROUND: Preconception care (PCC) defines health interventions prior to conception aimed at improving pregnancy and infant outcomes. AIM: To explore the understanding and provision of PCC by general practitioners (GPs) within the Sydney Local Health District. MATERIALS AND METHODS: A questionnaire developed with GPs assessed structure and content of PCC provided, attitudes toward PCC and perceived barriers and facilitators. RESULTS: One hundred and ten GPs completed the survey: 84% reported that GPs should be the main providers of PCC; however, only 53% were aware of PCC guidelines. Seventy-five percent of responders initiated PCC discussion with women of reproductive age, 56% provided PCC to women at higher risk of adverse outcomes and 16% waited for the discussion to be initiated by the patient. Smoking, vaccination, alcohol and supplements/medication use were the most discussed PCC components, while serology, full blood count and blood pressure were the most performed assessments. Most respondents stated that PCC is essential for women with pre-existing diabetes, previous pregnancy complications or chronic illness. However, only 45% stated PCC was essential for women >35 years and 39% for women who were overweight. Importantly, weight and mental health were among the least discussed PCC components. CONCLUSION: General practitioners are key providers of PCC; however, only half are aware of PCC guidelines and most do not recognise overweight to be a significant preconception issue. The most common barriers to PCC delivery were time constraints, lack of knowledge and lack of resources for patients. Improved resources and education are required to support adequate PCC provision.

Risk factors for antepartum stillbirth and the influence of maternal age in New South Wales Australia: a population based study.

BACKGROUND: Maternal age is a known risk factor for stillbirth and delayed childbearing is a societal norm in developed country settings. The timing and reasons for age being a risk factor are less clear. This study aimed to document the gestational specific risk of maternal age throughout pregnancy and whether the underlying causes of stillbirth differ for older women. METHODS: Using linkage of state maternity and perinatal death data collections the authors assessed risk factors for antepartum stillbirth in New South Wales Australia for births between 2002 - 2006 (n = 327,690) using a Cox proportional hazards model. Gestational age specific risk was calculated for different maternal age groups. Deaths were classified according to the Perinatal Mortality Classifications of the Perinatal Society of Australia and New Zealand. RESULTS: Maternal age was a significant independent risk factor for antepartum stillbirth (35 - 39 years HR 1.4 95% CI 1.12 - 1.75; ≥ 40 years HR 2.41 95% CI 1.8 - 3.23). Other significant risk factors were smoking HR 1.82 (95% CI 1.56 -2.12) nulliparity HR 1.23 (95% CI 1.08 - 1.40), pre-existing hypertension HR 2.77 (95% CI 1.94 - 3.97) and pre-existing diabetes HR 2.65 (95% CI 1.63 - 4.32). For women aged 40 or over the risk of antepartum stillbirth beyond 40 weeks was 1 in 455 ongoing pregnancies compared with 1 in 1177 ongoing pregnancies for those under 40. This risk was increased in nulliparous women to 1 in 247 ongoing pregnancies. Unexplained stillbirths were the most common classification for all women, stillbirths classified as perinatal infection were more common in the women aged 40 or above. CONCLUSIONS: Women aged 35 or older in a first pregnancy should be counselled regarding stillbirth risk at the end of pregnancy to assist with informed decision making regarding delivery. For women aged 40 or older in their first pregnancy it would be reasonable to offer induction of labour by 40 weeks gestation.

Stillbirth risk in a second pregnancy.

OBJECTIVE: To estimate the risk of stillbirth in a second pregnancy when previous stillbirth, preterm, and small-for-gestational age (SGA) births occurred in the previous pregnancy. METHODS: This was a population-based cohort study in New South Wales Australia from 2002 to 2006. Singleton births in a first pregnancy were linked to a second pregnancy using data from the New South Wales Midwives Data Collection and the New South Wales Perinatal Death Database. Deaths were classified according to the Perinatal Mortality Classifications of the Perinatal Society of Australia and New Zealand. Crude and adjusted hazard ratios were estimated using a proportional hazards model. RESULTS: Delivery of an SGA newborn in the first pregnancy was associated with increased risks of stillbirth in a second pregnancy (hazard ratio 1.73, 95% confidence interval [CI] 1.15-2.60) and risk was further increased with prematurity (hazard ratio 5.65, 95% CI 1.76-18.12). Stillbirth in a first pregnancy had a nonsignificant association with stillbirth in the second pregnancy (hazard ratio 2.03, 95% CI 0.60-6.90). For women aged 30-34 years, the absolute risk of stillbirth up to 40 completed weeks of gestation was 4.84 per 1,000 among women whose first pregnancy was a stillbirth and 7.19 per 1,000 among women whose first pregnancy was preterm and SGA. CONCLUSION: Delivering an SGA and preterm neonate in a first pregnancy is associated with greater risks for stillbirth in a second pregnancy than delivering a previous stillbirth. All factors merit improved surveillance in a subsequent pregnancy, and research should address underlying factors common to all three outcomes.

Major risk factors for stillbirth in high-income countries: a systematic review and meta-analysis.

BACKGROUND: Stillbirth rates in high-income countries have shown little or no improvement over the past two decades. Prevention strategies that target risk factors could be important in rate reduction. This systematic review and meta-analysis was done to identify priority areas for stillbirth prevention relevant to those countries. METHODS: Population-based studies addressing risk factors for stillbirth were identified through database searches. The factors most frequently reported were identified and selected according to whether they could potentially be reduced through lifestyle or medical intervention. The numbers attributable to modifiable risk factors were calculated from data relating to the five high-income countries with the highest numbers of stillbirths and where all the data required for analysis were available. Odds ratios were calculated for selected risk factors, from which population-attributable risk (PAR) values were calculated. FINDINGS: Of 6963 studies initially identified, 96 population-based studies were included. Maternal overweight and obesity (body-mass index >25 kg/m(2)) was the highest ranking modifiable risk factor, with PARs of 8-18% across the five countries and contributing to around 8000 stillbirths (≥22 weeks' gestation) annually across all high-income countries. Advanced maternal age (>35 years) and maternal smoking yielded PARs of 7-11% and 4-7%, respectively, and each year contribute to more than 4200 and 2800 stillbirths, respectively, across all high-income countries. In disadvantaged populations maternal smoking could contribute to 20% of stillbirths. Primiparity contributes to around 15% of stillbirths. Of the pregnancy disorders, small size for gestational age and abruption are the highest PARs (23% and 15%, respectively), which highlights the notable role of placental pathology in stillbirth. Pre-existing diabetes and hypertension remain important contributors to stillbirth in such countries. INTERPRETATION: The raising of awareness and implementation of effective interventions for modifiable risk factors, such as overweight, obesity, maternal age, and smoking, are priorities for stillbirth prevention in high-income countries. FUNDING: The Stillbirth Foundation Australia, the Department of Health and Ageing, Canberra, Australia, and the Mater Foundation, Brisbane, Australia.

Dopamine and ethanol cause translocation of epsilonPKC associated with epsilonRACK: cross-talk between cAMP-dependent protein kinase A and protein kinase C signaling pathways.

We found previously that neural responses to ethanol and the dopamine D2 receptor (D2) agonist 2,10,11-trihydroxy-N-propylnorapomorphine hydrobromide (NPA) involve both epsilon protein kinase C (epsilonPKC) and cAMP-dependent protein kinase A (PKA). However, little is known about the mechanism underlying ethanol- and D2-mediated activation of epsilonPKC and the relationship to PKA activation. In the present study, we used a new epsilonPKC antibody, 14E6, that selectively recognized active epsilonPKC when not bound to its anchoring protein epsilonRACK (receptor for activated C-kinase), and PKC isozyme-selective inhibitors and activators to measure PKC translocation and catalytic activity. We show here that ethanol and NPA activated epsilonPKC and induced translocation of both epsilonPKC and its anchoring protein, epsilonRACK to a new cytosolic site. The selective epsilonPKC agonist, pseudo-epsilonRACK, activated epsilonPKC but did not cause translocation of the epsilonPKC/epsilonRACK complex to the cytosol. These data suggest a step-wise activation and translocation of epsilonPKC after NPA or ethanol treatment, where epsilonPKC first translocates and binds to its RACK and subsequently the epsilonPKC/epsilonRACK complex translocates to a new subcellular site. Direct activation of PKA by adenosine-3',5'-cyclic monophosphorothioate, Sp-isomer (Sp-cAMPS), prostaglandin E1, or the adenosine A2A receptor is sufficient to cause epsilonPKC translocation to the cytosolic compartment in a process that is dependent on PLC activation and requires PKA activity. These data demonstrate a novel cross-talk mechanism between epsilonPKC and PKA signaling systems. PKA and PKC signaling have been implicated in alcohol rewarding properties in the mesolimbic dopamine system. Cross-talk between PKA and PKC may underlie some of the behaviors associated with alcoholism.

Ethanol operant self-administration in rats is regulated by adenosine A2 receptors.

BACKGROUND: Recent findings suggest that adenosine is involved in the neural and behavioral effects of ethanol (EtOH). Studies in neural cell culture show that EtOH, via activation of adenosine A2 receptors, triggers cyclic adenosine monophosphate/protein kinase A (cAMP/PKA) signaling and CRE (cAMP regulatory element)-mediated gene expression and that this effect is blocked by inhibiting G-protein betagamma subunits. Recently, we reported that expression of a betagamma inhibitor in the nucleus accumbens (NAc) reduces EtOH drinking in rats. The NAc expresses high levels of the adenosine A2A receptor in GABAergic medium spiny neurons. If the reinforcing effects of EtOH are mediated through an A2 activation of cAMP/PKA signaling via betagamma, then A2 receptor blockade should attenuate EtOH consumption. Here we tested this hypothesis. Because adenosine A2 and dopamine D2 receptors are coexpressed in neurons of the NAc, we compared the effects of A2 blockade with those of D2 receptor blockade. METHODS: Male Long-Evans rats were trained to self-administer 10% EtOH in daily 30-min sessions with an active and an inactive lever. Separate groups of rats were given the D2 antagonist eticlopride (0.005, 0.007, and 0.01 mg/kg), the A2 antagonist 3,7-dimethyl-1-propargylxanthine (DMPX; 1, 3, 5, 7, 10, and 20 mg/kg), and the A1 antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX; 0.125, 0.25, and 0.5 mg/kg) by systemic injection. RESULTS: Eticlopride dose-dependently reduced EtOH drinking. DMPX showed a bimodal effect: 10 and 20 mg/kg decreased, but 1 mg/kg increased, EtOH consumption. DPCPX was without effect. CONCLUSIONS: In support of our hypothesis, the A2 antagonist DMPX attenuated EtOH self-administration. Low doses of the A2 antagonist enhanced EtOH drinking, consistent with the possibility that rats increase EtOH self-administration to overcome partial A2 blockade. The D2 antagonist eticlopride also decreased EtOH self-administration. These data provide the first evidence that pharmacological modulation of adenosine A2 receptors can regulate EtOH consumption in rats.

State-specific monoclonal antibodies identify an intermediate state in epsilon protein kinase C activation.

Evaluation of the activation state of protein kinase C (PKC) isozymes relies on analysis of subcellular translocation. A monoclonal antibody, 14E6, specific for the activated conformation of epsilonPKC, was raised using the first variable (V1) domain of epsilonPKC as the immunogen. 14E6 binding is specific for epsilonPKC and is greatly increased in the presence of PKC activators. Immunofluorescence staining by 14E6 of neonatal rat primary cardiac myocytes and the NG108-15 neuroblastoma glioma cell line, NG108-15/D2, increases rapidly following cell activation and is localized to new subcellular sites. However, staining of translocated epsilonPKC with 14E6 is transient, and the epitope disappears 30 min after activation of NG-108/15 cells by a D2 receptor agonist. In contrast, subcellular localization associated with activation, as determined by commercially available polyclonal antibodies, persists for at least 30 min. In vitro, epsilonRACK, the receptor for activated epsilonPKC, inhibits 14E6 binding to epsilonPKC, suggesting that the 14E6 epitope is lost or hidden when active epsilonPKC binds to its RACK. Therefore, the 14E6 antibody appears to identify a transient state of activated but non-anchored epsilonPKC. Moreover, binding of 14E6 to epsilonPKC only after activation suggests that lipid-dependent conformational changes associated with epsilonPKC activation precede binding of the activated isozyme to its specific RACK, epsilonRACK. Further, monoclonal antibody 14E6 should be a powerful tool to study the pathways that control rapid translocation of epsilonPKC from cytosolic to membrane localization on activation.

Addicting drugs utilize a synergistic molecular mechanism in common requiring adenosine and Gi-beta gamma dimers.

The mesolimbic dopamine system and cAMP-dependent/protein kinase A (PKA) pathways are strongly implicated in addictive behaviors. Here we determine the role of dopamine D2 receptors (D2) in PKA signaling responses to delta-opioid (DOR) and cannabinoid (CB1) receptors. We find in NG108-15/D2 cells and in cultured primary neurons that a brief exposure to saturating concentrations of DOR and CB1 agonists increases cAMP, promotes PKA C alpha translocation and increases cAMP-dependent gene expression. Activation of PKA signaling is mediated by Gi-beta gamma dimers. Importantly, subthreshold concentrations of DOR or CB1 agonists with D2 agonists, which are without effect when added separately, together activate cAMP/PKA signaling synergistically. There is also synergy between DOR or CB1 with ethanol, another addicting agent. In all instances, synergy requires adenosine activation of adenosine A2 receptors and is mediated by beta gamma dimers. Synergy by this molecular mechanism appears to confer hypersensitivity to opioids and cannabinoids while simultaneously increasing the sensitivity of D2 signaling when receptors are expressed on the same cells. This mechanism may account, in part, for drug-induced activation of medium spiny neurons in the nucleus accumbens.

Cooperative activation of dopamine D1 and D2 receptors increases spike firing of nucleus accumbens neurons via G-protein betagamma subunits.

Dopamine in the nucleus accumbens modulates both motivational and addictive behaviors. Dopamine D1 and D2 receptors are generally considered to exert opposite effects at the cellular level, but many behavioral studies find an apparent cooperative effect of D1 and D2 receptors in the nucleus accumbens. Here, we show that a dopamine-induced enhancement of spike firing in nucleus accumbens neurons in brain slices required both D1 and D2 receptors. One intracellular mechanism that might underlie cooperativity of D1 and D2 receptors is activation of specific subtypes of adenylyl cyclases by G-protein betagamma subunits (Gbetagamma) released from the Gi/o-linked D2 receptor in combination with Galpha(s)-like subunits from the D1 receptor. In this regard, dopaminergic enhancement of spike firing was prevented by inhibitors of protein kinase A or Gbetagamma. Furthermore, intracellular perfusion with Gbetagamma enabled D1 receptor activation but not D2 receptor activation to enhance spike firing. Finally, our data suggest that these pathways may increase spike firing by inhibition of a slow A-type potassium current. These results provide evidence for a novel cellular mechanism through which cooperative action of D1 and D2 receptors in the nucleus accumbens could mediate dopamine-dependent behaviors.

betagamma Dimers mediate synergy of dopamine D2 and adenosine A2 receptor-stimulated PKA signaling and regulate ethanol consumption.

Dopamine release is activated by ethanol and addicting drugs, but molecular mechanisms linking dopaminergic signaling to neuronal responses and drinking behavior are poorly understood. We report that dopamine-D2 receptors induce PKA Calpha translocation and increase CRE-regulated gene expression. Ethanol also activates PKA signaling. Subthreshold concentrations of the D2 agonist NPA and ethanol, without effect alone, together cause synergistic PKA translocation and CRE-mediated gene transcription. D2 or adenosine A2 receptor blockade, pertussis toxin, Rp-cAMPS, or overexpression of dominant-negative peptides that sequester betagamma dimers prevent synergy. Importantly, overexpression of a betagamma inhibitor peptide in the nucleus accumbens strikingly reduces sustained alcohol consumption. We propose that synergy of D2 and A2 confers ethanol hypersensitivity and that betagamma dimers are required for voluntary drinking.

cAMP-dependent protein kinase types I and II differentially regulate cAMP response element-mediated gene expression: implications for neuronal responses to ethanol.

We have shown that ethanol induces translocation of cAMP-dependent protein kinase (PKA) to the nucleus, cAMP response element-binding protein (CREB) phosphorylation, and cAMP response element-mediated gene transcription in NG108-15 cells. However, little is known about which PKA types regulate this process. We show here that under basal conditions NG108-15 cells contain type I PKA (CbetaRIbeta) primarily in cytosol and type II PKA (CalphaRIIbeta) in the particulate and nuclear fractions. Antagonists of both type I and type II PKA inhibit forskolin- and ethanol-induced cAMP response element-mediated gene transcription. However, only the type II PKA antagonist inhibits forskolin-induced Calpha and ethanol-induced Calpha and RIIbeta translocation to the nucleus and CREB phosphorylation; the type I antagonist is without effect. Our data suggest that forskolin- and ethanol-induced CREB phosphorylation and gene activation are differentially mediated by the two types of PKA. We propose that type II PKA is translocated and activated in the nucleus and induces CREB phosphorylation that is necessary but not sufficient for gene transcription. By contrast, type I PKA is activated in the cytoplasm, turning on a downstream pathway that activates other transcription cofactors that interact with phosphorylated CREB to induce gene transcription.